Dr. Diana Chavkin: Oncofertility Gives Hope to Those Living with Cancer

Of the 700,000 cases of cancer diagnosed each year in the U.S., 10 percent are women of reproductive age. This means that there are more than 70,000 women diagnosed with cancer every year who may be considering having children. The most frequently diagnosed cancers in reproductive aged women are breast, uterine, cervical and ovarian. Because women are now waiting longer to have their first child, many receive this diagnosis before they have started their families. And because life-saving treatments may jeopardize a woman’s fertility, patients are faced with illness from cancer as well as the possibility of losing their ability to have children.

However, there is promising news for those confronted with a cancer diagnosis. First, doctors are detecting cancers earlier because of better screening techniques and more successful treatment. Second, improvements in treatment are giving patients better odds at long-term survival. Third, advances in reproductive medicine are providing patients more options to preserve their future fertility.

Gonadotoxic effects of cancer therapies
Breast cancer has one of the lowest cancer mortality rates and is the most common malignancy to affect women younger than 45. Unfortunately, the different cancer therapies used to save their lives may accelerate the loss of their fertility. Chemotherapy can cause egg depletion and may lead to ovarian failure. Radiation can affect ovarian function and impair hormone production. Women of all ages may be affected, but those exposed later in life will face the greatest impact. They may even experience early or premature menopause, depending on their age.

Not all chemotherapies have the same effect. Some are more toxic to ovarian function than others. Clinicians can use online resources to calculate the toxicity of chemotherapy (www.fertilehope.org/tool-bar/risk-calculator.cfm)

How does chemotherapy affect a woman’s menstrual cycle?
Chemotherapy and radiation can affect menses and, potentially, fertility. During cancer treatment, most women do not get a period. It may take six months to a year for a woman to start menstruating again after her treatment ends. The younger a woman is at the time of exposure, the higher the chance her periods will return. Women who are younger than 35 when exposed to chemotherapy have a 90 percent chance of recovery; those who are 40 have a 20 percent chance of resuming regular menses.

The return of menses does not mean the return of fertility, however. A fertility doctor will often perform hormonal blood tests and ultrasounds to assess the remaining fertility.

Women are told to avoid pregnancy while undergoing cancer treatment. Because a woman’s fertility declines with age and the risk of miscarriage increases, the delay is more significant for older reproductive aged women than for younger women.

Tamoxifen and breast cancer
Oncologists give tamoxifen to women with estrogen positive breast cancer for about five to 10 years. During this time, patients are instructed not to conceive. This extended period of time in which patients are told to avoid pregnancy may have the most significant impact on a woman’s fertility and her increased risk of miscarriage.

What can be done to limit the damage?
There are techniques surgeons and oncologists can use to minimize the harm to their patients’ fertility. These include:
– Offering less aggressive resection for uterine, ovarian and cervical cancers
– Planning radiation fields to shield the ovaries
– Moving ovaries out of the radiation field before treatment
– Using chemotherapy drugs less toxic to the ovaries, which the clinician must weigh against the effectiveness of the drugs
– Modifying doses
– Timing of treatment for breast cancer, such as delaying chemotherapy one month to allow for fertility preservation

In addition to delaying the administration of tamoxifen, doctors can schedule breaks in the middle of treatment so that pregnancy or fertility preservation can occur.

Using these techniques does not preclude patients from using fertility preservation options like egg, embryo or sperm freezing before treatment, which we strongly encourage and will discuss in the next blog.